No, I am calling the IsMoving function from the callback function in C++. The same thing happens when I try to call DoOEMButton, but the DoButton and GetDRO functions work just fine. I went through the plugin tutorial, and the file CMyScriptObject.h was built correctly. The functions are declared in the header file, yet the compiler (Visual Studio 2003) can't seem to resolve the IsMoving call. Everything else is working correctly.